Field Evaluation Of Four Sweet Potato Cultivars For Yield And Sweet Potato Weevil (<i>Cylas puncticollis</i> Boh.) Damage During The Early Cropping Season in South Eastern Nigeria

Abstract

Four sweet potato cultivars (TIS 87/0087, TIS 8441, TIS 2532 OP. 1. 13 and Ex Igbariam) were evaluated for yield and damage of C. puncticollis during the period June to October in 1999 and 2000, respectively. The trials were conducted in a randomized complete block design and replicated three times. Plants were sampled forthnightly for tuber yield and C. puncticollis incidence and damage. Marketable tubers were recorded at 8 weeks after planting (WAP) and this increased with the age of the plant. TIS 87/0087 consistently gave higher marketable tuber numbers at all the different times of harvesting than other cultivars. There was no incidence of C. puncticollis on tubers between 8 to 14 WAP. However, C. puncticollis damage was higher in 1999 than the year 2000 at 16 WAP. Although the percentage tubers infested and severity of damage did not significantly differ among the cultivars. TIS 2532. OP. 1. 13 showed consistent high incidence and severity of damage. [Niger Agric. J. 34 (2003): 81-86]